1. Field of the Invention
The present invention relates to an unauthorized apparatus detection device for detecting unauthorized devices produced by copying, and in particular, to technology for detecting clone playback devices used to play copyrighted content such as movies and music.
2. Description of the Related Art
In recent years the existence of clone devices produced by copying authorized playback devices has become a major problem. To protect copyright, only authorized devices are permitted to decrypt and playback encrypted content. However, each clone device has a device key identical to that held by an authorized playback device, and decrypts and plays encrypted content using a method identical to that used by the authorized playback device. Anyone in possession of the clone device can therefore fraudulently watch and listen to the content.
With regard to this problem, Patent Document 1 discloses a method for detecting clone terminals in the case where the authorized mobile terminal is a mobile phone.
According to Patent Document 1, a clone terminal detection device judges that a clone terminal exists if two or more mobile terminals are detected to be simultaneously under the control of a plurality of base stations.
Patent Document 1: Japanese Patent Application publication No. 2000-184447